The present invention relates generally to the field of vehicle seatbelts.
Seatbelts are installed in vehicles to increase passenger safety. A tongue, which is provided at an end of a seatbelt webbing, is fixed to engage with a buckle device on the floor of the vehicle. When the seatbelt is buckled the passenger is constrained by the seatbelt.
As disclosed for example in Japanese Patent Publication No. 2002-321593 (incorporated by reference herein) a seatbelt apparatus may include a wire strap. The wire-strap type buckle includes a buckle section with an opening at one end for inserting the tongue therein. The buckle section includes latch members that engage the inserted tongue; the buckle section is supported on both sides by a U-shaped frame so as to enable rotation of the buckle. The latch members are provided with two switches, one on a “hall” side and another on a “substrate” side for detecting engagement between the tongue and buckle.
Within the enclosure of the buckle, both ends of a wire are bent into two parts so as to form a loop (with overlapping portions) rotatably mounted to the vehicle floor. The looped portion of the wire is rotatably supported by a fixed member on the vehicle floor so that the enclosure is supported on the floor of the vehicle body and may swing freely therefrom. A protective cover (or boot) of an accordion shape is mounted between the enclosure and the fixed member for storing the wire and/or signal cables connected to the switches.
When a passenger engages the tongue of the seatbelt to the buckle device, an upper end of the buckle device is pulled in the longitudinal (or fore/aft direction) by a tensile force applied to the seatbelt. Therefore, the protective cover and the wire in the protective cover are bent in the longitudinal direction with respect to the vehicle. At this time, as shown in FIG. 6a-6b, for example, a portion of the protective cover 18 is significantly bent at an acute angle causing a concentrated bending stress in that area. The wire 14 may be significantly bent or crossed at a portion near the corresponding area(s) of the protective cover 18.
Accordingly, it is desirable to provide a seatbelt apparatus that can prevent the wire from being bent excessively or portions of the wire from intertwining when the seatbelt is buckled.